Blade clamping system for a jigsaw

ABSTRACT

The present disclosure relates to a jig saw blade clamp including a first clamp member defining a main slot. A second clamp member is positioned within the main slot. The first clamp member is moveable relative to the first clamp member between a first position in which the first and second clamp members are adapted to clamp a blade, and a second position in which the blade can be inserted between the first and second clamp members. A collar is pivotally moveable in first and second opposite directions relative to the first and second clamp members. The collar includes a cam portion that moves the second clamp member toward the first position when the collar is pivoted in the first direction, and also moves the second clamp member toward the second position when the collar is pivoted in the second direction.

FIELD OF THE INVENTION

The present invention relates generally to hand-held electric saws. Moreparticularly, the present invention relates to blade clamping systemsfor reciprocal saws such as jigsaws.

BACKGROUND OF THE INVENTION

Electrically powered jigsaws, also known as saber saws, are well knownin the art. A principle advantage of jigsaws over other types ofhand-held saws such as circular saws or band-type saws is the ability tomake curved cuts along relatively short radiuses. Consequently, jigsawsare particularly useful in performing tight scrolling cuts to cut curvesinto a work piece.

A conventional jigsaw typically includes an electric motor containedwithin a housing, and a shoe positioned beneath the housing. The shoeincludes a bottom surface adapted to slide or ride along the top surfaceof a work piece. An open-ended slot is formed at a front end of theshoe. A straight, bayonet-type saw blade extends downward from thehousing through the front slot. A leading edge of the blade includes aplurality of teeth that face in a forward direction toward the front ofthe shoe. In use, the blade is reciprocated in a generally up-and-downdirection by the motor. As the blade is reciprocated, the jigsaw ismanually advanced in a forward direction such that the teeth of theblade cut into a work piece. As the blade cuts into the work piece, thebottom surface of the shoe rides over the top of the work piece.

Some jigsaws are capable of producing an orbital blade motion. Such amotion has a rectilinear component of a generally up-and-down nature,and fore-and-aft motion advancing the cutting blade into the work piece.Typically, the blade advances on the cutting stroke, which isconventionally in the upstroke on most saws.

A variety of different blade types can be utilized with a jigsaw. Forexample, blades having different sizes, different teeth configurations,different teeth sizes, and different blade materials can be used. It isdesirable to have a blade clamping system that allows blades to bequickly and easily interchanged.

SUMMARY OF THE INVENTION

An aspect of the present invention relates to a blade clamp that allowsblades to readily be interchanged without requiring a tool.

Another aspect of the present invention relates to a single toollessblade clamp that can receive either universal or tang blades.

A further aspect of the present invention relates to a jig saw bladeclamp including a first clamp member defining a main slot. A secondclamp member is positioned within the main slot. The first clamp memberis moveable relative to the first clamp member between a first positionin which the first and second clamp members are adapted to clamp ablade, and a second position in which the blade can be inserted betweenthe first and second clamp members. A collar is pivotally moveable infirst and second opposite directions relative to the first and secondclamp members. The collar includes a cam portion that moves the secondclamp member toward the first position when the collar is pivoted in thefirst direction, and also moves the second clamp member toward thesecond position when the collar is pivoted in the second direction.

Still another aspect of the present invention relates to a jig saw bladeclamp including first and second clamp members moveable between a bladerelease position in which a blade can be inserted between and removedfrom between the first and second clamp members, and a clamping positionin which the first and second clamp members are adapted to clamp theblade thereinbetween. The first clamp member includes first and secondspaced-apart shoulders separated by a gap. The first and secondshoulders extend from the first clamp member toward the second clampmember, and are arranged and configured to trap a tang blade by engagingoppositely disposed tangs of a tang blade when the tang blade ispositioned within the gap. The second clamp member includes a projectionthat extends from the second clamp toward the first clamp. Theprojection is arranged and configured to fit within a mounting openingof a universal blade when the universal blade is positioned in the gapbetween the shoulders.

A variety of advantages of the invention will be set forth in part inthe description that follows, and in part will be apparent from thedescription, or may be learned by practicing the invention. It is to beunderstood that both the foregoing general description and the followingdetailed description are exemplary and explanatory only and are notrestrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated and constitute a partof the specification, illustrate several embodiments of the inventionand together with the description, serve to explain the principles ofthe invention. A brief description of the drawings is as follows:

FIG. 1 is a perspective view of an embodiment of a jigsaw constructed inaccordance with the principles of the present invention;

FIG. 2 is an exploded view of the jigsaw of FIG. 1;

FIG. 3 is a cross-sectional view longitudinally bisecting the jigsaw ofFIG. 1;

FIG. 4 is a perspective view of a shoe utilized by the jigsaw of FIG. 1;

FIG. 5 is a top view of the shoe of FIG. 4;

FIG. 6 is a bottom view of the shoe of FIG. 4;

FIG. 7a is a front view of the jigsaw of FIG. 1 with the blade orientedin a perpendicular cutting position relative to the base;

FIG. 7b is a front view of the jigsaw of FIG. 1 with the blade pivotedcounter-clockwise to a 45° angle cutting position relative to the base;

FIG. 7c is a front view of the jigsaw of FIG. 1 with the blade pivotedclockwise to a 45° cutting angle relative to the base;

FIG. 8 is a side view of the shoe of FIG. 4 with a dust wand connectedto the shoe.

FIG. 9 is a bottom view of the shoe of FIG. 8 with the sub-base removed.

FIG. 10 is a perspective view of a motor housing and pivot base utilizedby the jigsaw of FIG. 1;

FIG. 11 is a cross-sectional view that longitudinally bisects the motorhousing and pivot base of FIG. 10;

FIG. 12 is a bottom perspective view of the motor housing and pivot baseof FIG. 10;

FIG. 13a is a front view of a movable clamp member used by the bladeclamp shown in FIG. 2;

FIG. 13b is a left side view of the clamp member of FIG. 13a;

FIG. 13c is a top view of the clamp member of FIG. 13a;

FIG. 13d is a right side view of the clamp member of FIG. 13a;

FIG. 14a is a rear view of the movable clamp member of FIGS. 13a-13 d,the movable clamp is shown connected to a universal blade;

FIG. 14b is a left side view of the movable clamp and universal blade ofFIG. 14a;

FIG. 15a is a front view of a fixed clamp member that is used by theblade clamp shown in FIG. 2, the fixed clamp member is attached to ashaft;

FIG. 15b is a left side view of the clamp member and shaft of FIG. 15a;

FIG. 15c is a bottom view of the clamp member of FIG. 15a;

FIG. 16a is a front view of the fixed blade clamp of FIGS. 15a-15 c witha tang blade inserted therein;

FIG. 16b is a left side view of the fixed clamp and blade of FIG. 16a;

FIG. 17 is a perspective view of the moveable clamp member of FIGS.13a-13 d inserted within the fixed clamp member of FIGS. 15a-15 c;

FIG. 18 is a perspective view of an assembled blade clamp and bladeclamp shaft utilized by the jigsaw of FIG. 1;

FIG. 19 is another perspective view of the assembled blade clamp andblade clamp shaft used by the jigsaw of FIG. 1;

FIG. 20a is an elevational view of the blade clamp and blade clamp shaftof FIG. 19 with the blade clamp in a clamped position;

FIG. 20b is an elevational view of the blade clamp and blade clamp shaftof FIG. 20a with the blade clamp in an unclamped position;

FIG. 21a is a schematic bottom view of FIG. 20a; and

FIG. 21b is a schematic bottom view of FIG. 20b.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary aspects of the presentinvention which are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts.

FIG. 1 is a perspective view of an embodiment of a jigsaw 20 constructedin accordance with the principles of the present invention. Generally,the jigsaw 20 includes a housing 22 pivotally connected to a base orshoe 24. A front end of the shoe 24 defines an open-ended main slot 26.A blade clamp 28 is positioned above the main slot 26. A blade guide 30is positioned generally beneath the blade clamp 28. The blade guide 30is pivotally connected to the shoe 24 and is adapted to receive andlaterally support a jigsaw blade clamped within the blade clamp 28. Theterms “base” and “shoe” are intended to be used interchangeably.

In general use, a blade is inserted in the blade clamp 28 such that theblade extends downward through the blade guide 30 and also through themain slot 26. The teeth of the blade preferably face a forward directiontoward the open end of the slot 26, and at least a portion of the bladepreferably extends below a bottom surface of the shoe 24. When thejigsaw 20 is activated, the blade clamp 28 and its corresponding bladeare oscillated in a generally up-and-down motion. By placing the bottomsurface of the shoe 24 against a work piece, and moving the jigsaw 20 ina forward direction, the teeth of the reciprocating blade are broughtinto contact with the work piece thereby creating a cut in the workpiece.

FIGS. 2 and 3 provide a more detailed illustration of each of thecomponents of the jigsaw 20. Referring to FIG. 2, the shoe 24 of thejigsaw 20 includes a main base 32, a sub base 34 positioned below themain base 32, and a pivot base 36 positioned above the main base 32. Thesub base 34 is connected to the main base 32 by a plurality of bolts 38,while the pivot base 36 is connected to the main base 32 by bolt 40.Outer edges 42 of the pivot base 36 fit within longitudinal slots 44formed on the top of the main base 32. The bolt 40 extends through alongitudinally elongated opening 46 defined by the main base 32. Byloosening the bolt 40, the pivot base 36 can be slid longitudinallyalong the slots 44 relative to the main base 32. When the pivot base 36is oriented in a desired longitudinal position, the bolt 40 can betightened to clamp or retain the pivot base 36 in the desiredlongitudinal position relative to the main base 32.

The housing 22 of the jigsaw 20 includes several different components.For example, as shown in FIG. 2, the housing 22 includes a handle set 48and a gear housing set 50. Each of the sets 48 and 50 includes twoseparate pieces that are bolted together. The housing 22 also includes amotor housing 52 positioned behind the gear housing set 50.

The motor housing 52 is pivotally mounted on top of the pivot base 36.The motor housing 52 is connected to the pivot base 36 by a shoulderbolt 54 that extends upward through a curved slot 56 that extends acrossa width of the pivot base 36. A clamping structure is used to tighten orloosen the pivotal connection between the pivot base 36 and the motorhousing 52. The clamping structure includes a fixed ramp or wedge 58, amoveable ramp or wedge 60, and a threaded adjustment shaft 62. Byrotating the threaded adjusted shaft 62 in a first direction, the clampstructure is tightened such that pivotal motion between the pivot baseand the motor housing 52 is inhibited. By contrast, when the threadedadjustment shaft 62 is rotated in a second direction opposite to thefirst direction, the clamping structure is loosened thereby allowing themotor housing 52 to be manually pivoted relative to the pivot base 36.

An electric motor 64 is contained within the motor housing 52. The motor64 includes an armature portion 66 that is rotatably mounted within afield portion 68. The armature portion 66 includes a pinion gear 70 anda fan 72. The motor 64 receives electrical power through an electricalcord 74. A switch 76 controls the flow of electricity between theelectrical cord 74 and the motor 64.

The electric motor 64 functions to rotate the pinion gear 70 about agenerally longitudinal axis. The rotation of the pinion gear 70 isconverted into a reciprocal up and down motion by a drive mechanism 78.While a specific drive mechanism is shown and described, it will beappreciated that a variety of suitable drive arrangements or mechanismsare known in the art, and that any type of arrangement that generatesreciprocal up and down motion can be used in accordance with theprinciples of the present invention. In using the term up and downmotion, it is intended that such a term includes rectilinear up and downmotion as well as orbital up and down motion.

The drive mechanism 78 includes a main drive gear 80 that is rotatablymounted on a pin 82 secured to the gear housing 50. The main drive gear80 is rotated about the pin 82 by the pinion gear 70 of the motor 64. Acam 84, that is eccentric with respect to the pin 82, is formed on themain drive gear 80. A crank block 86 is bolted to the eccentric cam 84.An orbit lever 88 and a counterweight 90 are positioned between the maindrive gear 80 and the crank block 86.

The orbit lever 88 is pivotally mounted on a pin 92 secured to the gearhousing 50. The orbit lever 88 includes a u-shaped slot 94 that receivesthe eccentric cam 84 of the main drive gear 80. As the main drive gear80 is rotated, the eccentric cam 84 pivots the orbit lever 88 back andforth about the pin 92. As the orbit lever 88 is pivoted back and forth,a lower arm 96 of the orbit lever 88 engages a lever arm 98 causing thelever arm 98 to be reciprocated up and down. The lever arm 98 is part ofa roller holder 99 that includes a fork 100 in which a roller 102 isrotatably mounted. The roller holder 99 is pivotally mounted on a pivotpin 104. When the lever arm 98 is moved up and down by the orbit lever88, the roller holder 99 is pivoted back and forth about the pivot pin104. A rubber grommet 106 biases the lever arm 98 in an upwarddirection.

The roller holder 99 allows the jigsaw 90 to move a blade in an orbitalup and down motion. For example, when a jigsaw blade is inserted withinthe blade clamp 28, a rear portion of the blade engages the roller 102held by the roller holder 99. When the roller holder 99 is pivoted backand forth by the orbit lever 88, the roller 102 causes the blade to moveforward and backward. Concurrently, the blade is reciprocated in an upand down motion by the blade clamp 28. In this manner, the blade ismoved in an orbital up and down motion.

The amount of orbital motion provided to the blade is dependent upon theamount the roller holder 99 is pivoted about the pivot pin 104. In thisregard, the jigsaw 20 is provided with an orbital motion adjustmentmechanism for controlling the forward and backward movement of theblade. The adjustment mechanism includes an orbital motion adjustmentshaft 108 including a cam surface 110 that engages the lever arm 98 ofthe roller holder 99. A knob 112 is used to rotate the shaft 108. Byrotating the shaft 108, a spacing between the lever arm 98 and the lowerarm 96 of the orbit lever 88 can be adjusted. For example, when theshaft 108 is in a first position, the cam surface 110 allows the leverarm 98 to be in close proximity to the lower arm 96 of the orbit lever88. Consequently, a maximum amount of orbital motion is generated. Bycontrast, when the shaft 108 is in a second position, the cam surface110 pushes the lever arm 98 a sufficient distance away from the lowerarm 96 of the orbit lever 88 such that the orbit lever 88 fails tocontact the lever arm 98 when the main gear 80 is rotated. As a result,no orbital motion is generated. It will be appreciated that the shaft108 can be oriented at intermediate positions between the first andsecond positions in order to achieve intermediate amounts of orbitalmotion.

The counterweight 90 of the drive mechanism 78 includes an opening 114that is elongated in a lateral direction. The eccentric cam 84 isreceived within the opening 114 such that the counterweight isreciprocated up and down as the main drive gear 80 is rotated. It willbe appreciated that the reciprocation of the counterweight 90 is 180degrees out of phase with respect to the reciprocation of a bladesecured to the jigsaw 20.

The crank block 86 of the drive mechanism 78 is used to convert therotational motion of the drive gear 80 into rectilinear motion. Forexample, the crank block 86 is used to reciprocate a blade holder shaft116 in an up and down motion. The blade clamp 28 is connected to a lowerend of the blade holder shaft 116. The blade clamp 28 includes a fixedclamp member 130 that is fixedly connected to the bottom of the bladeholder shaft 116, a moveable clamp member 132 that is moveable withrespect to the fixed clamp member 130, a collar 134 that is mounted overboth the fixed and moveable clamp members 130 and 132, and a coil spring136.

The crank block 86 includes a pin 118 on which a roller 120 is mounted.The roller 120 fits within a lateral slot 122 formed in a drive bracket124. The blade holder shaft 116 is fixedly clamped between the drivebracket 124 and a drive clamp 126. The blade holder shaft 116 is alsoslidably mounted in a bearing holder assembly 126 that is pivotallymounted on a shaft 128 secured to the gear housing 50.

As the crank block 86 is rotated by the main drive gear 80, the roller120 is laterally reciprocated within the lateral slot 122 and causes thedrive bracket 124 to be oscillated up and down. Because the blade holdershaft 116 is fixedly clamped between the drive bracket 124 and the driveclamp 125, the reciprocation of the drive bracket 124 also causes ablade holder shaft 116 to be reciprocated in an up and down motion. Asthe blade holder shaft 116 is reciprocated in an up and down motionrelative to the bearing holder assembly 126, the shaft 128 allows thebearing holder assembly 126 to pivot to accommodate orbital motion of ablade secured to the blade secured within the blade clamp 28.

FIGS. 4-6 provide various views of the shoe 24 in isolation from theremainder of the jigsaw 20. Referring to FIGS. 4-6, the blade guide 30is connected to the pivot base 36 of the shoe 24 and is positionedwithin the main slot 26 defined by the shoe 24. As positioned in theslot 26, the blade guide 30 is preferably relatively close to the subbase 34. Consequently, when the jigsaw 20 is used to cut a workpiece,the blade guide 30 is positioned relatively close to the workpiecethereby enhancing the amount of lateral support provided to the blade.

The blade guide 30 is pivotally connected to a front portion 138 of thepivot base 36. The front portion 138 includes a sleeve 140 defining acylindrical bore 139 aligned along a longitudinal axis L—L of the shoe24. The blade guide 30 is pivotally mounted within the bore 139 of thesleeve 140. The blade guide 30 is retained in the sleeve 140 by a snapring 148 that engages the rear side of the sleeve 140, and a radialshoulder 150 that engages a front side of the sleeve 140.

A front portion 146 of the blade guide 30 projects forwardly from thepivot base 36 into the main slot 26 of the shoe 24. The front portion146 defines a front blade slot 152 sized for receiving a jigsaw blade.The front blade slot 152 has an open end that faces the front of theshoe 24. The blade guide 30 is aligned along and pivotally moveableabout the longitudinal axis L—L.

The blade slot 152 of the blade guide 30 is formed by two spaced-apartprojections 154. For example, the blade slot 152 is defined by opposing,generally planar inner surfaces 156 of the projections 154. The bladeslot 152 is wide enough to allow a blade to freely reciprocate withinthe blade slot 152. While the blade is reciprocated, the inner surfaces156 provide lateral support that resists twisting of the blade. Incertain embodiments of the present invention, a threaded pin (notshown), or other type of pin, can extend transversely through theprojections 154 into the slot 152. Such a pin is adapted to engage theblade within the blade slot 152. In this manner, the pin functions toeffectively narrow the width of the slot 152.

As previously described, the position of the pivot base 36 can belongitudinally adjusted relative to the main base 32. For example, byloosening bolt 40, the pivot base 36 can be slid longitudinally alongslots 44 and along the elongated opening 46 formed through the main base32. By adjusting the longitudinal position of the pivot base 36 relativeto the main base 32, the longitudinal position of the blade guide 30within the main slot 26 can also be adjusted.

Referring now to FIG. 7a, a schematic front view of the jigsaw 20 isillustrated. As shown in FIG. 7a, the blade guide 30 is positioned inthe main slot 26 and is in close proximity to a bottom surface 141 ofthe sub base 34. The inner surfaces 156 defining the blade slot 152 areshown facing and in close proximity to opposite lateral surfaces 158 ofa blade 160.

Still referring to FIG. 7a, the pivot base 36 includes a convex surface162 that is centered on or swung about the longitudinal axis L—L.Additionally, the housing 22 includes a concave surface 164 that iscentered on or swung about the longitudinal axis L—L. The concavesurface 164 is adapted to slide relative to the convex surface 162 whenthe housing 22 is pivoted relative to the pivot base 36.

The blade guide 30, the blade 160, and the housing 22 are all pivotallymoveable about the same longitudinal axis L—L. To adjust a cutting angleof the blade 160 relative to the shoe 24, the housing 22 and blade 160are pivoted as a unit about the longitudinal axis L—L. As the housing 22and blade 160 are pivoted, contact between the blade 160 and the bladeguide 30 causes the blade guide 30 to concurrently pivot about thelongitudinal axis L—L. FIG. 7a shows the blade 160 aligned at aperpendicular cutting position relative to the bottom surface 141 of theshoe 24. FIG. 7b shows the blade 160 pivoted clockwise to a 45 degreecutting angle relative to the bottom surface 141 of the shoe 24. FIG. 7cshows the cutting blade 160 pivoted counterclockwise to a 45 degreecutting angle relative to the bottom surface 141 of the shoe 24.

FIGS. 8 and 9 illustrate an exemplary dust collection system used by thejigsaw 20. Referring to FIG. 9, the dust collection system includes adust chamber 166 integrally formed beneath the main base 32. AlthoughFIG. 9 shows the dust chamber 166 with the sub base 34 removed, it willbe appreciated that when the sub base 34 is secured to the main base 32,the sub base 34 effectively seals the dust chamber 166.

Referring again to FIG. 9, the dust chamber 166 includes an outlet port168 formed at the rear of the main base 32, and two inlet ports 170positioned on opposite sides of the main slot 26 defined by the shoe 24.The inlet ports 170 are positioned on opposite sides of the blade 160and are arranged and configured to suction sawdust generallytransversely away from the lateral surfaces 150 of the blade 160. Inother words, the inlet ports 170 draw dust laterally away from thelateral surfaces 158 as shown by arrows 172. For certain embodiments ofthe present invention, the inlet ports 170 draw or suction dust in adirection generally transverse with respect to the longitudinal axis L—Lof the sub base 24.

The dust chamber 166 provides fluid communication between the outletport 168 and the inlet ports 170. Specifically, the dust chamber 166includes a main portion 174 and two channel portions 176 that are influid communication with the main portion 174. The two channel portions176 branch outward from the main portion 174 and include portions thatare laterally spaced apart and generally parallel. The channel portions176 extend along opposite sides of the main slot 26 and each channelportion 176 is in fluid communication with a respective one of the inletports 170. In use of the dust collection system, an external source ofvacuum is placed in fluid communication with the outlet port 168. Thesource of vacuum creates a vacuum within the dust chamber 166 thatcauses air and dust to be drawn into the dust chamber 166 through theinlet ports 170. From the inlet ports 170, the evacuated air and dusttravel through the channel portions 176 to the main portion 174, andexit the dust chamber 166 through the outlet port 168.

To facilitate connecting a source of vacuum to the outlet port 168, anadapter or dust wand 178 can be used. The dust wand 178 has one end thatsnaps or friction fits within the outlet port 168, and a second endadapted for connection to an external source of vacuum. For example, avacuum hose can be friction fit over the second end of the dust wand178. The dust wand 178 also includes a tab 180 that fits within anaperture defined by the rear of the housing 22 to provide verticalsupport to the dust wand 178.

FIGS. 10-12 illustrate a base clamping mechanism arranged and configuredfor selectively clamping the housing 22 at desired pivot locationsrelative to the shoe 24. As previously described with respect to FIG. 2,the base clamping mechanism includes the threaded adjustment shaft 62,the fixed ramp or wedge 58, the moveable ramp or wedge 60, and theshoulder bolt 54. The shoulder bolt 54 connects the pivot base 63 to themotor housing 52. For example, as shown in FIG. 11, the shoulder bolt 54extends upward through the curved slot 56 defined by the pivot base 36and also through a circular opening 182 defined by the motor housing 52.The circular opening 182 is defined by a lower wall 184 of the motorhousing 152, while the curved slot 56 is defined by a curved upper wall186 of the pivot base 36. An upper end of the shoulder bolt 54 isthreaded within a captured nut 188 mounted within the motor housing 52.The captured nut 188 is mounted to resist rotation, and the shoulderbolt 54 is preferably threaded within the captured nut 188 such that ashoulder 190 of the shoulder bolt 154 presses against the bottom surfaceof the captured nut 188.

The fixed wedge 58 and the moveable wedge 60 are mounted on the shoulderbolt 54. For example, referring again to FIG. 11, the shoulder bolt 190extends through a circular aperture 192 defined by the fixed wedge 58and an elongated opening 194 defined by the moveable ramp 60. Thecircular aperture 192 has a diameter that is generally equal to theouter diameter of the shoulder bolt 54. The elongated opening 194 iselongated in a forward direction that is generally parallel to thelongitudinal axis L—L of the shoe 24.

Both the fixed wedge 58 and the moveable wedge 60 are captured ortrapped between the curved upper wall 186 of the pivot base 36 and ahead 196 of the shoulder bolt 54. The moveable wedge 60 is mounted abovethe fixed wedge 58. The fixed wedge 58 includes a bottom surface 198that engages the head 196 and is generally transversely aligned withrespect to the shaft of the shoulder bolt 54. Additionally, the fixedramp 58 also includes a top surface 200 aligned at an acute angle withrespect to the bottom surface 198. The top surface 200 inclines upwardin a forward direction with respect to the shoe 24.

The moveable wedge 60 includes a top surface 202 that engages the curvedupper wall 186 of the pivot base 36, and a bottom surface 204 thatengages the top surface 200 of the fixed wedge 58. The top surface 202is generally transversely aligned with respect to the shaft of theshoulder bolt 54, and the bottom surface 204 is aligned at an acuteangle with respect to the top surface 202. The bottom surface 204 of themoveable wedge 60 is generally parallel with respect to the top surface200 of the fixed wedge 58.

The fixed and moveable ramps 58 and 60 cooperate with the shoulder bolt54 to selectively clamp the motor housing 52 relative to the pivot base36. When the clamping mechanism is tightened or clamped, the motorhousing 52 is inhibited from pivoting relative to the pivot base 36about the longitudinal axis L—L. By contrast, when the clampingmechanism is released, loosened or unclamped, the motor housing 52 canbe manually pivoted relative to the pivot base 36 about the longitudinalaxis L—L with minimal resistance.

To tighten the clamping mechanism, the moveable wedge 58 is forced in aforward direction relative to the fixed wedge 58. As the moveable wedge60 moves in the forward direction, the moveable wedge 60 is wedgedbetween the top surface 200 of the fixed wedge 58 and the bottom surfaceof the curved upper wall 186 of the pivot base 36. Such a wedge actionplaces an axial tension on the shoulder bolt 54 and causes the lowerwall 184 of the motor housing 52 and the upper wall 186 of the pivotbase 36 to be drawn together. For example, the wedge action pushes thehead 196 of the shoulder bolt 54 downward relative to the upper wall 186of the pivot base 36 causing the shoulder bolt 54 to pull downward onthe captured nut 188. As the captured nut 188 is pulled downward, thelower wall 184 of the motor housing 52 and the upper wall 186 of thepivot base 36 are compressed together. As the lower and upper walls 184and 186 are compressed together by the shoulder bolt 54, enhancedfriction is generated between the concave surface 164 of the motorhousing 52 and the convex surface 162 of the pivot base 36. Suchenhanced friction resists movement of the motor housing 52 relative tothe pivot base 36. Consequently, the motor housing 52 is effectivelylocked or clamped relative to the pivot base 36.

To release the clamping mechanism, the moveable wedge 60 is moved in arearward direction relative to the fixed wedge 58. As the moveable wedge58 moved rearward, the head 196 of the shoulder bolt 54 is allowed tomove toward the curved upper wall 186 thereby reducing the pressurebetween the lower wall 184 of the motor housing 52 and the upper wall186 of the pivot base 36. As the pressure is reduced, the frictionbetween the convex and concave surfaces 162 and 164 is also reduced suchthat the motor housing 52 can be manually pivoted relative to the pivotbase 36. When the motor housing 52 is pivoted relative to the pivot base36, the shoulder bolt 54 slides along the curved slot 56 defined by thepivot base 36. Once the motor housing 52 has been moved to a desiredpivot location, the clamp mechanism is re-tightened to retain thehousing 52 in the desired position.

Referring to FIGS. 10 and 11, the pivot base 36 also defines a pluralityof depressions 206. The depressions 206 are arranged and configured toreceive ball detents 208 mounted within the motor housing 52. The balldetents 208 are biased downward by detent springs 210. Each of thedepressions 206 corresponds to a particular cutting angle that may bedesired. For example, the depressions 206 can be located at positionscorresponding to a perpendicular cutting angle as well as cutting anglesof 15 degrees, 30 degrees, and 45 degrees offset from perpendicular. Theball detents 208 and depressions 206 help a user quickly and preciselyset the jigsaw 20 at a desired cutting angle.

It will be appreciated that a variety of arrangements can be used tomove the moveable wedge 60 relative to the fixed wedge 58. As shown inFIGS. 11 and 12, the threaded adjustment shaft 62 is used to control theposition of the moveable wedge 60. The adjustment shaft 62 is alignedgenerally parallel with respect to the longitudinal axis L—L and isrotatably mounted in a downwardly opening slot 212 formed in the motorhousing 52. The adjustment shaft 62 is retained in the slot 212 by across pin 214. A flange 216 limits axial movement of the adjustmentshaft 62 relative to the motor housing 52 and the pivot base 36. Forexample, as shown in FIG. 11, the flange is captured between the motorhousing 52 and the pivot base 36.

The adjustment shaft 62 has a threaded end 218 having external threads.The threaded end 218 is threaded within a longitudinal slot 220 definedby the moveable wedge 60. The longitudinal slot 220 includes internalthreads that mate with the external threads of the threaded end 218.When the adjustment shaft 62 is rotated in a first direction, theinternal and external threads cooperate to force the moveable wedge 60in the forward direction toward the fixed wedge 58. By contrast, whenthe adjustment shaft 62 is rotated in a second direction opposite to thefirst direction, the internal and external threads cooperate to pull themoveable wedge 60 rearward away from the fixed wedge 58.

The adjustment shaft 60 is also equipped with a lever arm 222 forincreasing the manual torque that can be applied to the adjustment shaft62. The lever arm 222 is telescopically mounted within a handle portion224 of the adjustment shaft 62. By telescopically extending the leverarm 222 outward from the handle portion 224, and pivoting the lever arm222 90 degrees about pivot pin 226, the lever arm 222 can be used toincrease the manual torque applied to the adjustment shaft 62.

Referring back to FIG. 2, the basic components of the blade clamp 28used by the jig saw 20 include the fixed clamp member 130, the moveableclamp member 132, the collar 134, and the coil spring 136. Whenassembled, the blade clamp 28 is adapted to releasably clamp or secure ablade to the bottom end of the blade holder shaft 116.

Referring now to FIGS. 13a-13 d, various views of the moveable clampmember 132 are shown. The moveable clamp member 132 includes a main body300. A clamping face 264 and an inner follower surface 260 are formed onopposite sides of the main body 300. First and second axially alignedprojections 302 and 303 project transversely outward from the clampingface 264. The first projection 302 is generally cylindrical, while thesecond projection 303 has a ramped surface 305. The moveable clampmember 132 also includes a rounded end 304 and transverse wings 306 thatproject transversely outward from the main body 300.

The first and second projections 302 and 303 are arranged and configuredto secure a universal blade to the moveable clamp member 132. Forexample, FIGS. 14a and 14 b show the moveable clamp member 132 connectedto a universal blade 324. As shown in FIGS. 14a and 14 b, the secondprojection 303 of the moveable clamp member 132 fits within an opening326 of the universal blade 324, while first projection 302 of themoveable clamp member 132 fits within a top notch 328 formed on theuniversal blade 324. The projections 302 and 303 of the moveable clampmember 132 inhibit axial movement of the universal blade 324 relative tothe moveable clamp member 132.

Referring back to FIGS. 13a-13 d, the moveable clamp member 132 alsoincludes a jaw lever 246 that projects outward from the inner followersurface 260. The jaw lever 246 includes an extension 250 connected tothe main body 300 of the moveable clamp member 132. The jaw lever 246also includes a distally located jaw tab 248 having outer followersurfaces 262 positioned on opposite sides of the extension 250. Theouter follower surfaces 262 on the jaw tab 248 generally oppose theinner follower surface 260 formed on the main body 300.

FIGS. 15a-15 c illustrate the fixed clamp member 130 of the blade holder28. The fixed clamp member 130 is fixedly connected to the bottom end ofthe blade holder shaft 116. The shaft 116 includes a slot 117 forfacilitating clamping the shaft 116 between the drive bracket 124 andthe drive clamp 126 (shown in FIG. 2).

Referring to FIGS. 15a-15 c, the fixed clamp member 130 includes a mainaxial slot 252 aligned along a longitudinal axis A—A of the shaft 116.The main axial slot 252 is sized for receiving the moveable clamp member132. A curved end 253 of the main axial slot 252 is sized to receive therounded end 304 of the moveable clamp member 130. A secondary axial slot255 defined by the fixed clamp member 130 is sized to receive the firstand second projections 302 and 303 of the moveable clamp member 130 whenthe moveable clamp member 132 is mounted within the main axial slot 252.

The fixed clamp member 130 also includes first and second transverseslots 308 and 310. The first transverse slot 308 is sized and shaped toreceive tangs of a tang blade. The second transverse slot 310 isarranged and configured to receive the transverse wings 306 of themoveable clamp member 132 when the moveable clamp member 132 is mountedwithin the main axial slot 252. The first and second transverse slots308 and 310 are defined by first, second and third shoulders sets 312,313 and 314. Each of the shoulder sets 312, 313 and 314 includes aseparate shoulder positioned on opposite sides of a gap 316 thatcorresponds to the width of the main axial slot 252. The gap 316 issized for receiving either a tang blade or a universal blade.

FIGS. 16a and 16 b show the fixed clamp member 130 with a tang bladetrapped therein. As shown in FIGS. 16a and 16 b, oppositely disposedtangs 320 of the tang blade 319 fit within the first transverse slot 308of the fixed clamp member 130. The first and second shoulder sets 312and 313 inhibit axial movement of the blade 319 relative to the fixedclamp member 130.

FIG. 17 illustrates the fixed clamp member 130 with the moveable clampmember 132 mounted in the main axial slot 252. As shown in FIG. 17, thetransverse wings 302 of the moveable clamp member 132 fit within thesecond transverse slot 310 of the fixed clamp member 130. The transversewings 306 function to transfer axial loading from a universal blademounted on the moveable clamp member 132 directly to the blade holdershaft 116 through the fixed clamp member 130.

FIGS. 18 and 19 provide assembled views of the blade clamp 28. As shownin FIGS. 18 and 19, the moveable clamp member 132 is mounted in the mainaxial slot 252 of the fixed clamp member 130 (as shown in FIG. 17). Thecollar 134 is mounted over both the fixed clamp member 130 and themoveable clamp member 132. The collar 134 is pivotally moveable relativeto the fixed and moveable clamp members 130 and 132 about thelongitudinal axis A—A of the shaft 116. The spring 136 is mounted overthe shaft 116 and has a first end 230 fixedly secured relative to thecollar 134 (as shown in FIG. 19), and a second end 232 fixedly securedrelative to the shaft 116 (as shown in FIG. 18).

Referring now to FIGS. 20a and 20 b, the collar 134 defines acircumferential slot 234 having a first end 240 positioned opposite froma second end 244. The collar 134 also defines an axial access slot 236located adjacent to the second end 244 of the circumferential slot 234.The collar 134 further includes a radial collar tab 242 positionedadjacent to the first end 240 of the circumferential slot 234. Theextension 250 of the jaw lever 246 extends outward through thecircumferential slot 234, and jaw tab 248 is positioned outside thecollar 134.

The collar 134 is pivotally moveable off the longitudinal axis A—Abetween a blade clamping position (shown in FIG. 20a) where the bladeclamp 28 is adapted to clamp a blade, and a blade release position(shown in FIG. 20b) where a blade can be inserted into or removed fromthe blade clamp 28. In the blade clamping position, the jaw lever 246 islocated adjacent to the second end 244 of the circumferential slot 234.In the blade release position, the jaw lever 246 is located adjacent tothe first end 240 of the circumferential slot 234. The spring 136 biasesthe collar 134 toward the blade clamping position.

A user preferably moves the collar 134 from the position of clampingposition of FIG. 20a to the blade release position of FIG. 20b bymanually pushing the collar and jaw tabs 242 and 248 toward one another.As the collar and jaw tabs 242 and 248 are pushed toward one another,the collar 134 pivots about the longitudinal axis A—A against resistanceprovided by the spring 136. Also, as the collar 134 is pivoted, relativemovement is generated between the circumferential slot 234 and the jawlever 246 such that the first end 240 of the circumferential slot 234moves toward the jaw lever 246. With the blade clamp 28 manually held inthe position of FIG. 20b, a blade can be inserted in the blade clamp 28.Once the blade is inserted in the blade clamp 28, the collar and jawtabs 242 and 248 can be released thereby allowing the spring 136 toreturn the blade clamp 28 to the position of FIG. 20a.

FIG. 21 a is a bottom view of the blade clamp 28 showing the blade clamp28 in the blade clamping position of FIG. 20a. In the blade clampingposition, the clamping face 264 of the moveable clamp member 232 is inclose proximity to the corresponding clamping face 266 formed on thefixed clamp member 130. FIG. 21a is a bottom view of the blade clamp 28showing the blade clamp 28 in the blade release position of FIG. 20b. Asshown in FIG. 21b, the moveable clamp member 132 is pulled away from thefixed clamp member 130 such that a relative large spacing S existsbetween the clamping faces 264 and 266. The spacing is preferablysufficiently large to allow a jigsaw blade to be inserted between theclamping faces 264 and 266, or removed from between the clamping faces264 and 266.

A cam mechanism is used to move the moveable clamp member 232 betweenthe clamping position of FIG. 21a and the blade release position of FIG.21b. For example, as shown in FIGS. 21a and 21 b, the collar 134includes a cam wall or portion 254 that curves gradually away from theaxis A—A of rotation of the collar 134. The circumferential slot 234(shown in FIGS. 20a and 20 b) is formed through the cam portion 254.Referring to FIGS. 21a and 21 b, the cam portion 254 includes inner camsurfaces 256 and outer cam surfaces 258. The inner cam surfaces 256 faceor engage the inner follower surface 260 formed on the moveable clampmember 232. Similarly, the outer cam surfaces 258 face or engage outerfollower surfaces 262 formed by the jaw tab 248.

With respect to FIG. 21a, by pivoting the collar 134 in acounterclockwise direction about the axis of rotation A—A, the collartab 242 is moved toward the jaw tab 248. As the collar 134 is pivoted,the cam portion 154 of the collar 134 slides along the moveable clampmember 132. As the cam portion 254 slides relative to the moveable clampmember 132, the outer cam surfaces 258 engage the outer followersurfaces 262 causing the moveable clamp member 132 to be pulled awayfrom the fixed clamp member 130. In this manner, the moveable clampmember 132 is moved from the blade clamping position of FIG. 21a to theblade release position of FIG. 21b.

After a blade has been inserted into or removed from between theclamping faces 264 and 266, the collar tab 242 can be released causingthe spring to pivot the collar 134 clockwise about the pivot axis A—A.As the collar 134 pivots clockwise about the pivot axis A—A, the innerfollower surface 260 engages the inner cam surfaces 256 causing themoveable clamp member 132 to be pushed toward the fixed clamp member130. In this manner, the moveable clamp member 132 is moved from theblade release position of FIG. 21b back to the clamping position of FIG.21a.

The blade clamp 28 is preferably assembled by first placing the moveableclamp member 132 within the main axial slot 253 of the fixed clampingmember 130. Next, the collar is inserted over the shaft 116 and sliddownward over both the moveable and fixed clamp members 132 and 130. Asthe collar 134 is slide downward, the collar is oriented such that thejaw lever 246 is received in the axial access slot 236. The jaw lever246 travels through the access slot 236 and enters the circumferentialslot 234. Once the jaw lever is positioned in the circumferential slot234, the spring 136 is slid over the shaft 116 and positioned on top ofthe collar 134. Finally, the first end 230 of the spring 136 is fixedlysecured to the collar 134, and the second end 232 of the spring 136 isfixedly secured to the shaft 116.

With regard to the foregoing description, it is to be understood thatchanges may be made in detail, especially in matters of the shape, sizeand arrangement of the parts without departing from the scope of thepresent invention. It is intended that the specification and depictedembodiment be considered exemplary only, with a true scope and spirit ofthe invention being indicated by the broad meaning of the followingclaims.

We claim:
 1. A jigsaw blade clamp comprising: a first clamp memberdefining a main slot; a second clamp member positioned within the mainslot, the second clamp member being moveable relative to the first clampmember between a first position in which the first and second clampmembers are adapted to clamp a blade, and a second position in which theblade can be inserted between the first and second clamp members; and acollar being pivotally moveable in first and second opposite directionsrelative to the first and second clamp members, the collar including acam portion that moves the second clamp member toward the first positionwhen the collar is pivoted in the first direction, and also moves thesecond clamp member toward the second position when the collar ispivoted in the second direction.
 2. The blade clamp of claim 1, whereinthe first clamp member is fixedly connected to a reciprocating shaft. 3.The blade clamp of claim 1, wherein at least one of the first and secondclamp members includes a projection arranged and configured to fitwithin a mounting opening of a universal blade.
 4. The blade clamp ofclaim 1, wherein at least one of the first and second clamp membersincludes a first projection arranged and configured to fit within amounting opening of a universal blade, and a second projection arrangedand configured to fit within a top notch of the universal blade.
 5. Theblade clamp of claim 4, wherein the first projection is ramped.
 6. Theblade clamp of claim 1, wherein at least one of the first and secondclamp members includes a transverse slot arranged and configured fortrapping the oppositely disposed tangs of a tang blade.
 7. The bladeclamp of claim 3, wherein at least one of the first and second clampmembers includes a transverse slot arranged and configured for trappingthe oppositely disposed tangs of a tang blade.
 8. The blade clamp ofclaim 7, wherein the projection is formed on the second clamp member,and the transverse slot is defined by the first clamp member.
 9. Theblade clamp of claim 1, wherein the first clamp member includes firstand second shoulders positioned on opposite sides of the main slot, theshoulders being arranged and configured for engaging oppositely disposedtangs of a tang blade.
 10. The blade clamp of claim 9, wherein theprojection is formed on the second clamp member and extends toward thefirst clamp member into the main slot.
 11. The blade clamp of claim 1,wherein at least one of the first and second clamp members defines atransverse slot, and the other of the first and second clamp membersincludes transverse projections that fit within the transverse slot toallow axial loading to be transferred between the first and second clampmembers.
 12. The blade clamp of claim 11, wherein the transverse slot isformed by the first clamp member, and the transverse projections areformed on the second clamp member.
 13. The blade clamp of claim 1,further comprising a spring that biases the collar in the firstdirection.
 14. The blade clamp of claim 1, wherein the cam portion ofthe collar curves gradually away from a pivot axis of the collar. 15.The blade clamp of claim 14, wherein the cam portion defines acircumferential slot, and the second clamp member includes an extensionmember that extends through the circumferential slot.
 16. The bladeclamp of claim 15, wherein the second clamp member includes a tabpositioned at a distal end of the extension member at a location outsidethe collar.
 17. A jigsaw blade clamp comprising: first and second clampmembers moveable between a blade release position in which a blade canbe inserted between and removed from between the first and second clampmembers, and a clamping position in which the first and second clampmembers are adapted to clamp the blade thereinbetween; the first clampmember including first and second spaced-apart shoulders separated by agap, the first and second shoulders extending from the first clampmember toward the second clamp member, the first and second shouldersbeing arranged and configured to trap a tang blade within the bladeclamp by engaging oppositely disposed tangs of a tang blade when thetang blade is positioned within the gap; the second clamp memberincluding a projection extending from the second clamp member toward thefirst clamp member, the projection being arranged and configured to fitwithin a mounting opening of a universal blade when the universal bladeis positioned in the gap between the shoulders; and wherein the firstblade clamp includes a transverse slot, and the second blade clampincludes transverse wines that fit within the transverse slot.
 18. Theblade clamp of claim 17, wherein the projection is positioned in generalaxial alignment with the gap between the first and second shoulders. 19.A jigsaw blade clamp comprising: a first clamp member; a second clampmember having a portion that opposes the first clamp member, the secondclamp member being moveable relative to the first clamp member between afirst position in which the first and second clamp members are adaptedto clamp a blade, and a second position in which the blade can beinserted between the first and second clamp members; a collar that ispivotally moveable in first and second opposite directions relative tothe first and second clamp members, the collar including a cam portionfor positively moving the second clamp member between the first andsecond positions, the second clamp member being forced by the camportion toward the first position when the collar is pivoted in thefirst direction, and the second clamp member being forced by the camportion toward the second position when the collar is pivoted in thesecond direction; and a spring that urges the collar to pivot in thefirst direction.
 20. The blade clamp of claim 19, wherein the camportion of the collar curves gradually away from a pivot axis of thecollar.
 21. The blade clamp of claim 20, wherein the cam portion definesa circumferential slot, and the second clamp member includes anextension member that extends through the circumferential slot.
 22. Theblade clamp of claim 21, wherein the second clamp member includes afinger grip positioned at a distal end of the extension member at alocation outside the collar.
 23. The blade clamp of claim 22, wherein anouter surface of the cam-portion engages the finger grip to positivelymove the second clamp member toward the second position when the collaris pivoted in the second direction.